We have recently published our new Zipcode/house number lookup plugin for nopCommerce 3.8 and up.
Upon entering a zipcode and housenumber, the plugins contacts the address lookup service from www.insidertrader.biz.
When an address is valid it will automatically set the street and city and mark the address green.
When an address is invalid it will mark the address red.
Since the _CreateOrUpdateAddress.cshtml is overruled by our version one can easily add other features like presenting a list of number extensions to pick from.